1. Field of the Invention
The present invention relates generally to packet communication systems and more specifically to a technique for establishing a connection in a packet-switched network, using a signaling packet. The present invention is particularly suited for asynchronous transfer mode (ATM) switched networks.
2. Description of the Related Art
Routing addresses used in an ATM-switched network are defined by the CCITT Recommendations E. 164 and are known as ISDN (integrated services digital network) addresses or E. 164 addresses. According to the CCITT Recommendations E. 164, each port of any node of an ATM network is uniquely identified by a port address composed of an area code, a node number and a port number. In local area networks (LAN), user terminals are identified by a network address as defined by a network layer protocol such as Internet Protocol. If one or more private LAN's is to be supported by an ATM network, address resolution is necessary to convert the network address of a destination user to a port address before establishing a connection. This requires a source user terminal to broadcast an address conversion request to destination user terminals or inquire an address translation server, thus generating a substantial amount of undesired overhead traffic which increases disproportionately as the network size increases. In addition, multi-protocol users of different protocols coexist in a local area network. Multi-protocol routers are available for supporting such applications. However, no universal address scheme exists that can be used in common by the different protocols. If an ATM system were to be operated in a multi-protocol environment, one approach would be to provide an address resolution protocol for each user terminal for converting a network address to a corresponding E. 164 address. However, a substantial amount of burden is placed on the user for protocol processing. Another approach is to simultaneously operate a plurality of protocol routers in parallel fashion. However, each node of the network would be required to simultaneously operate different protocols. This results in system complexity.